• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.132-141
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• 2024

In this study, the differences in user satisfaction and the variables influencing the satisfaction with demand response transport (DRT) by travel purpose were compared. The purpose of DRT travel was divided into commuting/school and shopping/leisure travel. A survey conducted on 'Shucle' users in Sejong City was used for the analysis and the least absolute shrinkage and selection operator (LASSO) regression analysis was applied to minimize the overfitting problems of the multilinear model. The results of the analysis confirmed the possibility that the introduction of the DRT service could eliminate the blind spot in the existing public transportation, reduce the use of private cars, encourage low-carbon and public transportation revitalization policies, and provide optimal transportation services to people who exhibit intermittent travel behaviors (e.g., elderly people, housewives, etc.). In addition, factors such as the waiting time after calling a DRT, travel time after boarding the DRT, convenience of using the DRT app, punctuality of expected departure/arrival time, and location of pickup and drop-off points were the common factors that positively influenced the satisfaction of users of the DRT services during their commuting/school and shopping/leisure travel. Meanwhile, the method of transfer to other transport modes was found to affect satisfaction only in the case of commuting/school travel, but not in the case of shopping/leisure travel. To activate the DRT service, it is necessary to consider the five influencing factors analyzed above. In addition, the differentiating factors between commuting/school and shopping/leisure travel were also identified. In the case of commuting/school travel, people value time and consider it to be important, so it is necessary to promote the convenience of transfer to other transport modes to reduce the total travel time. Regarding shopping/leisure travel, it is necessary to consider ways to create a facility that allows users to easily and conveniently designate the location of the pickup and drop-off point.

• Annual Conference of KIPS
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• 2024.05a
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• pp.108-111
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• 2024

클라우드 사용이 보편화 되고 확대됨에 따라, 서비스를 유연하게 확장 및 축소하여 신속하게 시장의 수요에 대응할 수 있는 PaaS(Platform-as-a-Service) 형태의 서비스가 많은 기업에서 각광받고 있다. 그리고 이러한 PaaS 형 서비스의 핵심이 되는 기술인 컨테이너(Container)와 컨테이너 관리를 효율화 해주는 쿠버네티스(Kubernetes)가 실질적인 표준으로 사용되고 있다. 이때 쿠버네티스 기반의 환경에서 서비스 어플리케이션은 다양한 구성사례가 존재하나, DB 는 아직 안정성 및 데이터 정합성 등을 이유로 베어메탈(Baremetal)이나 VM(Virtual Machine)을 기반으로 구성하고 있는 상황이다. 그러나, 인프라 구성 및 운영에 있어서도 파드(Pod) 형태의 DB 구성은 베어메탈 및 VM 대비 장점이 존재한다고 생각하여 본 실험을 수행하였다. 본 논문에서는 서비스 응답시간 및 자원 사용의 효율성 측면에서 VM 기반의 DB 와 쿠버네티스 파드 기반의 DB 에 각각 트래픽을 발생시켜서 비교한 결과와 시사점을 제시한다.

• Convergence Security Journal
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• v.24 no.3
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• pp.117-129
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• 2024

With the announcement of Transformer, a new type of architecture, in 2017, there have been many changes in language models. In particular, the development of LLM (Large language model) has enabled generative AI services such as search and chatbot to be utilized in various business areas. However, security issues such as personal information leakage and reliability issues such as hallucination, which generates false information, have raised concerns about the effectiveness of these services. In this study, we aimed to analyze the factors that are increasing the frequency of using generative AI in the workplace despite these concerns. To this end, we derived eight factors that affect the quality of LLM-based generative AI response data and empirically analyzed the impact of these factors on job satisfaction using a valid sample of 195 respondents. The results showed that expertise, accessibility, diversity, and convenience had a significant impact on intention to continue using, security, stability, and reliability had a partially significant impact, and completeness had a negative impact. The purpose of this study is to academically investigate how customer perception of response data quality affects business utilization satisfaction and to provide meaningful practical implications for customer-centered services.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.23-30
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• 2017

OpenADR is a national standard communication protocol of demand response service. OpenADR uses XML message, called a payload, to support logical transaction of demand response service. For this purpose, OpenADR defines a XML element as transaction identifier which is called requestID. Unfortunately, OpenADR 2.0b profile specification describes some information about requestID but, it is not enough for understanding properly. Ambiguous definition of payload transaction makes vulnerabilities of implementing VEN & VTN and confuses mapping OpenADR 2.0b protocol into other smart grid protocols. Therefore, this paper redefines payload transaction to solve an ambiguous information of OpenADR 2.0b profile specification, proposes a model of analyzing payload transaction, and shows how to detect a payload transaction vulnerability in real-world.

• Annual Conference of KIPS
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• 2014.11a
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• pp.41-44
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• 2014

최근 클라우드 컴퓨팅에 관련된 기술이 각광을 받으면서, 기존에 인터넷을 통해 제공되던 다양한 서비스들이 클라우드 컴퓨팅 플랫폼 환경으로 이동하고 있다. 이를 통해 사용자들에게는 좀 더 편리하고 유연한 서비스를 제공하고 서비스 제공자들에게는 기존 관리 비용의 절감을 할 수 있게 되었다. 하지만 현재 폭발적인 수요의 증가로 인해, 기존의 자원 활용도의 극대화를 목적으로 고안된 자원 분배 기법들에 대한 여러 한계점이 나타나게 되었다. 본 논문에서는 이러한 문제점들을 해결하고자 클라우드 컴퓨팅 환경에서 Qos를 기반으로 사용자나 서비스 제공자의 비용적인 측면을 고려한 자원분배를 통해 서비스를 제공시 사용자 요구를 만족시키고 동시에 서비스 공급자에게는 비용 효율적인 프로비저닝(Provisioning)기법을 제안하고자 한다. 실험 결과 기존의 자원 활용도에 중점을 둔 기법보다 사용자 요청에 대한 응답 속도가 8.35% 향상되었으며, 컴퓨터 자원 유지 관련 비용면에서도 기존 대비 11.31% 절감 효과를 가져오는 것을 확인 할 수 있었다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.219-232
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• 2023

Mobility services need to change according to the regional characteristics of the target service area. Accordingly, analysis of mobility patterns and characteristics based on Origin-Destination (OD) data that reflect travel behaviors in the target service area is required. However, since conventional methods construct the OD data obtained from the administrative district-based zone system, it is hard to ensure spatial homogeneity. Hence, there are limitations in analyzing the inherent travel patterns of each mobility service, particularly for new mobility service like Demand Responsive Transit (DRT). Unlike the conventional approach, this study applies a data-driven clustering technique to conduct spatial analyses on OD travel patterns of regional mobility services based on reconstructed OD data derived from re-aggregation for original OD distributions. Based on the reconstructed OD data that contains information on the inherent feature vectors of the original OD data, the proposed method enables analysis of the spatial characteristics of regional mobility services, including public transit bus, taxi and DRT.

• Journal of Information Management
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• v.43 no.4
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• pp.143-167
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• 2012

In this study, survey analysis was conducted to determine the demands of science & technology information service by the groups of users. The questionnaire was composed of the need for 20 services in the science & technology information, the need for personal information to people-to-people exchanges, and information that can be shared with others. KOSEN users 1,013 people participated in the survey, and the analysis of variance was conducted depending on institution, profession, final degree and the age of the respondents. Results of frequency analysis, there were in high demands for trend analysis, papers, research reports, patents, knowledge queries, project announcements, jobs, experimental methods, information society and study abroad/Post-doc information, and all services except mentoring, community and blog were appeared to have the significant differences depending on the groups of users. Also the personal information deemed to be necessary for interaction with others was resulted in specialization, thesis/research performances, career, organization, jobs, final degree and education in order, there were partially difference depending on the user's groups. In addition, 97% of respondents had their own scientific and technical information to be shared with other people in order of papers, presentations (ppt), reports, experimental methods and the images. The results of this study can be used as useful information for scientists and engineers to develop a user-centered personalized services and are expected to be helpful to set the direction of science information services in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.1
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• pp.57-65
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• 2022

Gyeongsangnam-do has been operating Bravo-taxi, a Gyeongnam-type DRT using taxi vehicles, since 2017 to guarantee the right of mobility for residents who live in areas lacking public transportation. This research investigated and analyzed changes in users' awareness over two years from beginning of Bravo-taxi operation in Gyeongsangnam-do, which started operating Bravo-taxis in 2017, targeting sites lacking public transportation. Through this study, the positive effects of taxi-type DRT were confirmed, such as improving the mobility of residents in areas underprivileged by public transportation, reducing required time for trips, and increasing preference for Bravo-taxis compared to existing buses. On the other hand, problems with the current Bravo-taxi system were also identified. In some areas, it was found that there were not enough coupons for Bravo-taxis, or in the case of Bravo-taxis operating at fixed times, the user's desired time and operating time did not match, resulting in lower satisfaction. The results of this research are expected to be utilized as basic data for service continuity of taxi-type DRT in operation by other local governments.

• Journal of the Korean Society for Railway
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• v.17 no.2
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• pp.94-99
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• 2014

Recently, trends in new transportation system development have been primarily focused on sustainable and ecofriendly mobility solutions. The personal rapid transit (PRT) system has been considered a promising candidate in this category; its competitiveness is being improved through convergence with cutting-edge electric vehicle (EV) technologies. However, battery-powered vehicles pose difficult technical challenges in attempts to achieve reliable and efficient operation. In this study, a design approach for a solar-power assisted PRT system is presented with small-scale demonstrations aimed at circumventing challenges facing its adoption, as well as helping speed the transition to electric-powered ground transportation. From the results, it is expected that flexible photovoltaic (PV) cells will be able to supply 11% of the power required by the service equipment installed in a prototype vehicle. In particular, flexible photovoltaic (PV) cells are advantageous in terms of cost, weight, and design considerations. Most importantly, the cells' flexibility and attach-ability are expected to give them great potential for extended application in various areas.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.571-577
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• 2012

Recently, improving public transport service at disabled people has emerged as a social issue in rural areas. By improving expensive and inefficient existing operating system, the rural bus have to change a personalized service. Under these circumstances, government and local governments are promoting the introduction of DRT(Demand response transport). DRT system is intended to promote the user's convenience. But, until now, in-depth research on the operating costs for the introduction of DRT is not well known. This study aims to look at changes in number of vehicle and operating costs before and after introduction of DRT. The results are as follows. Even though introducing DRT, total number of vehicles increases because it does not reduce the existing number of vehicles. And this study estimated to about 5 to 12 percent of the increase in the operating cost comparing before introduction of DRT. Therefore, The introduction of DRT in rural areas is a need to set the exact purpose as promote transportation convenience or cost efficiency.